The present invention is directed to a working tool holder for a drilling or chiseling device and to a working tool. The working tool holder includes a holder sleeve with an opening for the insertion shaft of a working tool. An axially extending section of the opening tapers conically inwardly. Pins mounted in the holder sleeve can be moved generally radially into the holder opening by means of a spring force. The pins extend tangentially or chordally relative to the holder opening. Inwardly projecting ridges are located in the holder opening for engagement in corresponding grooves in the insertion shaft. Further, the insertion shaft has recesses for seating the pins. An actuating sleeve axially displaceable relative to the holder sleeve is arranged for moving the pins relative to the holder opening.
A working tool holder is known in DE-A No. 1-34 34 076 and insures an exact centric guidance and reliable axial support of the inserted working tool during a drilling operation. At the commencement of the drilling operation, such high transverse or shearing forces develop, due to the lack of lateral guidance of the working tool, that the working tool may become loosened.